﻿Shader "Unlit/ImageLerp"
{
	Properties
	{
		_MainTex("FirstTexure", 2D) = "white" {}
		_SecondTex("SecondTexure", 2D) = "white" {}
		_LerpWeight("MixValue 0 only First,1 only Second", Range(0, 1)) = 0
	}
	SubShader
	{
		Tags { "RenderType"="Opaque" }
		LOD 100
		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			
			#include "UnityCG.cginc"

			struct appdata
			{
				float4 vertex : POSITION;
				float2 uv : TEXCOORD0;
			};

			struct v2f
			{
				float2 uv : TEXCOORD0;
				float4 vertex : SV_POSITION;
			};

			sampler2D _MainTex;
			sampler2D _SecondTex;
			float4 _MainTex_ST; // _FirstTex与_SecondTex用同一个
			
			float _LerpWeight;

			v2f vert (appdata v)
			{
				v2f o;
				o.vertex = UnityObjectToClipPos(v.vertex);
				o.uv = TRANSFORM_TEX(v.uv, _MainTex);
				return o;
			}
			
			fixed4 frag (v2f i) : SV_Target
			{
				fixed4 col = lerp(tex2D(_MainTex, i.uv), tex2D(_SecondTex,i.uv), _LerpWeight);
				return col;
			}
			ENDCG
		}
	}
}
